Fuel pump gasket

Abstract

Provided is a gasket for a fuel pump unit configured with a second outlet port for accommodating a pressure sensor to monitor the downstream pressure of pumped fuel. The gasket is adapted for placement between a pump cover incorporating the second outlet port and a pump body containing a gear pump. Providing fluid communication between a first outlet port downstream of the gear pump and the second outlet port is a passageway disposed through the pump cover and pump body. To avoid obstructing the passageway, the gasket includes an aperture. To prevent high pressure fuel from being forced through the gasket and leaked from the pump unit, the gasket includes a leakage collection channel having a first leg, a second leg and an intermediate portion surrounding the aperture. The leakage collection channel is adapted to return leaked fuel to a low pressure reservoir between the pump cover and pump body.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No. 10/461,152, entitled “Port Configuration for Fuel Pump Unit for Facilitating Pressure Feedback” filed on Jun. 11, 2003. This patent application claims the benefit of U.S. Provisional Patent Application No. 60/571,834, filed on May 17, 2004.

FIELD OF THE INVENTION

The present invention relates generally to sealing devices and more particularly to gaskets for sealing fuel pumps. The present invention finds particular use in fuel pumps having a port configuration of the type disclosed in U.S. application Ser. No. 10/461,152.

BACKGROUND OF THE INVENTION

Fuel oil pump units are used to pump fuel oil to oil burning furnaces for heating residential and commercial buildings. By virtue of the application and where furnaces are located, fuel oil pump units often are required to fit a small confined area of a predetermined package size. Examples of fuel oil pump units are disclosed in U.S. Pat. Nos. 3,360,190; 3,446,230; 3,446,231; 3,446,232; 3,566,901; 4,021,155; 4,171,939; 4,255,093; 4,391,580; 4,685,871; 4,728,271; 4,856,553; 4,858,884; 4,898,523; 4,958,997; 5,145,328; 5,316,457; 5,346,174; and 5,692,680, and application Ser. Nos. 10/017,153 and 10/115,742, all assigned to the present assignee and all of which are hereby incorporated by reference in their entireties.

As disclosed in these patents and applications, the basic structural design for a fuel oil pump unit typically comprises a pump body often formed of cast iron and a pump cover often formed of aluminum. The pump body typically contains a crescent type gear pump that pumps fuel oil from a local reservoir defined between the pump body and pump cover that is supplied oil from a fuel oil storage tank. A gasket may be provided for sealing the local reservoir. The downstream portion of the gear pump is in communication with a nozzle outlet passage in the pump body that is adapted to be connected to the combustion chamber of a furnace. The basic structural design has been incorporated in one or more standardized package configurations in which the dimensions and port configurations are largely pre-determined.

To monitor and provide electronic feedback regarding the fuel oil pump unit, vacuum and pressure sensors may be incorporated with the fuel oil pump unit upstream and downstream of the gear pump. Incorporation of the sensors is problematic, however, because the sensors must not alter the standardized package configuration of the pump unit.

One solution to incorporating the pressure sensors into existing standardized package configurations is provided in U.S. application Ser. No. 10/461,152 assigned to the present assignee and herein incorporated by reference in its entirety. The invention disclosed in U.S. application Ser. No. 10/461,152 provides for an additional outlet port disposed through the pump cover and connected via a passageway to the nozzle outlet passage downstream of the gear pump. A sensor attached to the additional outlet port is therefore in fluid communication with downstream pressure generated by the gear pump.

Since the passageway must pass through the pump cover and pump body to communicate with the nozzle outlet passage, there exists a potential for fuel leakage between the pump body and cover. Specifically, because the passageway experiences a higher pressure than the surrounding environment, fuel oil may be forced along the mating surfaces of the pump body and pump cover and leak or spray from the pump unit. This results in an extremely hazardous condition where the leaked fuel may ignite causing an explosion. It is therefore desirable to prevent such fuel leaks from occurring.

SUMMARY OF THE INVENTION

The present invention prevents fuel leakage between the pump cover and pump body by providing a gasket for placement therebetween. The gasket, which may also seal the local reservoir, is specially adapted to seal the passageway between the pump cover and the pump body. To provide communication along the passageway between the second outlet port and the nozzle outlet passage, the gasket includes an aperture that aligns with the passageway. Surrounding the aperture is a sealing ring of gasket material that seals the passageway.

Because fuel oil may be forced through or around the sealing ring, the gasket also includes a leakage collection channel surrounding the aperture and spaced therefrom by the sealing ring. The leakage collection channel is formed from a plurality of straight legs generally set in the gasket in a generally U-shaped arrangement. The collection channel is positioned between the aperture and the outer periphery of the gasket and includes a first leg and a second leg arranged so as to communicate with the low pressure local reservoir upstream of the gear pump when the fuel oil pump unit is assembled. Accordingly, any fuel oil forced past the sealing ring will be collected in the leakage collection channel and returned to the local reservoir.

An advantage of the present invention is that the gasket enables downstream pressure to be communicated across the passageway to the second outlet port. Another advantage is that high pressure fuel oil in the passageway is substantially sealed therein by a sealing ring. Another advantage of the present invention is that fuel oil forced from the passageway is collected into a leakage collection channel and returned to the low pressure local reservoir. These and other advantages and features of the present invention will be apparent from the detailed description and accompanying drawings.

Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:

FIG. 1 is a schematic representation of a oil pump unit incorporated in a oil pumping system for a furnace or boiler, in accordance with a preferred embodiment of the present invention;

FIG. 2 is a perspective view of the oil pump unit shown in FIG. 1 as it is hooked up to a burner according to an embodiment of the present invention;

FIG. 3 is a top view of the oil pump unit shown in FIG. 1;

FIG. 4 is a frontal view of the oil pump unit shown in FIG. 2;

FIG. 5 is a bottom view of the oil pump unit shown in FIGS. 2 and 4;

FIG. 6 is a cross section of FIG. 5 taken about line 6-6 with a different type of regulating valve shown in comparison to FIG. 1;

FIG. 7 is a cross section of FIG. 4 taken about line 7-7;

FIG. 8 is an exploded view of an embodiment of a pump unit employing a gasket between the pump body and pump cover;

FIG. 9 is a front elevational view of the gasket illustrated in FIG. 8; and

FIG. 10 is a rear elevational view of a pump cover for use with a pump unit employing a gasket of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

As shown in the drawings, the invention is embodied in a fuel oil pump unit 10 of the type used to supply fuel to the combustion chamber 11 of a burner such as might be incorporated into a furnace or boiler. The unit 10 includes a gear pump 15 that draws fuel oil or other suitable fuel from an oil supply such as a tank 12 through an intake line 13.

The gear pump 15 is contained within a pump housing that is comprised of a pump body 14 (preferably made of case iron) and a pump cover 16 (preferably made of aluminum). The pump cover 16 is bolted to the pump body 14. The gear pump 15 is illustrated as the conventional crescent type and includes an inner gear 17 within the housing that is attached to a drive shaft 18 and that is eccentrically disposed with respect to an outer gear 19. A crescent-shaped member 20 is disposed between the non-engaging portions of the teeth on the gears for the purpose of sealing the expanding fluid chambers defined by the gears from the contracting fluid chambers in a well known manner.

The pump shaft 18 is journalled in the pump body 14 and is sealed with respect thereto by an elastomeric sealing member which herein is shown in the form of a lip seal 22. The lip seal 22 is disposed within and seals off a lubrication chamber 23 in the housing.

The pump 15 includes an inlet side that communicates with a local fuel oil reservoir 26 that receives fuel oil from the main oil supply or tank 12. The pump cover defines an inlet port 28 to which the intake line 13 (often provided by copper tubing) from the storage tank 12 may be connected. The local fuel oil reservoir 26 is defined in a chamber formed between the pump body 14 and the pump cover 16. More specifically, the pump cover 16 includes a front side 48 and a rearwardly extending sidewall 50 that spaces the front side 48 forward of the pump body 14 and that encloses the fuel reservoir 26.

A suitable strainer 30 may be located within the reservoir 26 between the inlet port 28 and the pump inlet 25 to filter the fuel oil as it is drawn from the tank to the pump 15. The pump 15 pressurizes the fuel oil and outputs fuel into an outlet passage 32 along the downstream side of the pump 15. A bleed valve 33 may be disposed along the outlet passage 32. The outlet passage 32 ultimately delivers fuel oil to a main regulating valve assembly 34 that serves to regulate the pressure of fuel oil and causes fuel flow to the burner 36 to be of a substantially constant pressure.

The regulating valve assembly 34 is located in the pump body 14 and serves to control the fuel flow from the outlet passage 32 to an outlet port 41 defined by the pump body 41. A fitting 39 may be mounted into the outlet port 41 of the pump body 14. Copper tubing 38 or other suitable conduit means is mounted to the fitting 39 to connect the outlet port 41 of the pump body 14 to the burner 36.

The fitting 39 also provides a valve seat 40 for the regulating valve assembly 34. The valve seat 40 is adapted to be closed by a spring biased hollow piston 42. The piston 42 is slidably mounted in a pressure chamber 44 and is spring biased to regulate fuel flow enter the chamber 44.

The opening and closing of the regulating valve assembly 34 is controlled with a solenoid valve 58 that is mounted to the top side of the pump body 14. As shown herein, the solenoid valve 58 is of the blocking type, but it alternatively may be of the bypassing type or other suitable control arrangement. The solenoid valve 34 controls opening of the regulating valve assembly 34 (i.e., the outlet port of valve assembly 34) to the outlet passage 32 upon startup and controls closing of the regulating valve assembly 34 upon shut down. The solenoid valve 58 includes an electrical control element 66 drives a movable valve element 62 between open and closed states to cause pressure to build or be relieved such that the spring biased piston 42 either opens or closes a bypass passage 60 that recirculates fuel to either the tank 12 or local reservoir 26.

The electric control element 66 may include a thermistor providing a desired time delay for switching the solenoid valve between states. Alternatively, an electronic control (not shown) for the burn may provide the means to control activation of the solenoid control element. In either event, a delay is typically provided in order to provide sufficiently high pump speed and fuel pressure; and also to allow the speed of the blower (not shown), which is driven by the same shaft 18 as the pump 15 to be sufficient to establish a good draft up the chimney 72 of the burner 36.

The disclosed embodiment may also or alternatively include a diaphragm valve 74 or other similar bypass mechanism arrange in parallel circuit with the first bypass mechanism of the solenoid valve 58 and/or the regulating valve assembly 34. in the disclosed embodiment, the diaphragm valve serves as a redundant backup to the solenoid valve 58 to better ensure the proper opening of the fuel regulating valve assembly 34 at an appropriate time. Such a redundant bypass arrangement is disclosed in patent application Ser. No. 10/017,153 filed on Dec. 14, 2001. The diaphragm valve 74 causes the pump 15 to reach a high start-up rpm before the regulating valve assembly 34 opens and causes the regulating valve assembly to close after the pump 15 falls below a certain rpm upon shutdown. The diaphragm valve 74 is adapted to open or close a second return passage 81 leading back to the pump reservoir 26 (or alternatively to the tank 12). To provide for proper operation of the diaphragm valve, a cone valve 82 is arranged upstream of the diaphragm valve to provide a restriction and pressure drop that determines when the diaphragm valve 74 closes the second return passage 81.

As long as the speed of the pump 15 is relatively low, the diaphragm valve 74 remains open to prevent a build up of pressure in the chamber 44 of the regulating valve assembly 34 sufficiently such that the regulating valve assembly 34 remains closed via the spring biased piston 42. However, as the pump speed increases, the increased flow past the cone valve 82 causes a pressure differential in the diaphragm valve to overcome the force of a seeping and close the diaphragm valve causing all of the fuel flow to flow from the pump 15 through the outlet passage of the pump body 14 to the regulating valve assembly 34.

In the disclosed embodiment, the diaphragm valve 74 acts as a back up for the solenoid valve 58 to better ensure that smoking or soot production does not occur in the combustion chamber 11. The regulating valve assembly 34 remains closed as long as either the diaphragm valve 74 remains open or the solenoid valve 58 remains closes, thereby causing the piston 41 to be wide open and cause flow to bypass along bypass passage 60. The regulating valve assembly 34 opens and outputs fuel to the furnace only after the diaphragm valve 74 closes and the solenoid valve 58 opens. Once this happens (which is typically very quickly), all of the fuel flow is pumped by the gear pump 15 through the outlet passage 32 and the outlet port 41.

In accordance with the present invention, the oil pump unit 10 provides a port arrangement that substantially maintains size package of prior solenoid type models, while also accommodating inlet side and outlet side electronic pressure gauges 84, 86. As is evident from the foregoing, one inlet port 28 is provide to receive fuel from the tank 12, and one outlet port 41 is provided to output pressurized fuel o the burner 36.

To accommodate the inlet side electronic pressure gauge 84 at least one additional inlet side port 88 is provide in the bottom side of the pump body 14. The inlet side port 88 is constantly in fluid communication with the local reservoir 26 and subject to the pressure experienced in the local reservoir 26 upstream of the pump 15. As a result, the pressure experienced at the inlet side pressure gauge 84 is the vacuum pressure that is upstream of the pump 15. The inlet side pressure gauge 84 provides electronic feedback representing sensed vacuum pressure on an electrical line 90 which may be transmitted via telephone lines or a wireless transmitter to a remote location. Such data that is transmitted over the electrical line 90 is indicative of whether the oil pump unit 10 is properly operating.

To accommodate the outlet side electronic pressure gauge 86, an outlet side port 92 is formed into the front side of the pump cover 16. Because the pump cover 16 is upstream of the pump 15, a formed passage 94 is provided though the pump cover 16 and the pump body 14 that bypasses the reservoir 26 to be in direct fluid communication with the outlet port 41 on the downstream side of the pump 15 and downstream of the solenoid valve 58. With this arrangement, the outlet side port 92 is in constant communication with the pressure generated by the pump when the solenoid valve 58 is open. With the given arrangement, downstream of the solenoid valve 58, the outlet side pressure gauge 86 will also indicate if the solenoid valve and regulating valve assembly are properly operating. The outlet side pressure gauge 86 is mounted into the outlet side port 92 and provides electronic feedback on an electrical line 96. The pressure gauge data on electrical line 96 may be transmitted on telephone lines or a wireless transmitter to a remote location.

The data from the pressure gauges 84, 86 can be used at a remote location to determine whether the oil pump unit 10 is properly operating. If the data indicates a problem, a service technician can be sent to maintenance, repair or replace the oil pump unit 10. The source of the problem might also be indicated by the gauges 84, 86 such that the service technician can anticipate the solution and be prepared during a maintenance visit.

The illustrated pump unit 10 also provides a port arrangement that is suitable for use with existing applications. For purposes of orientation, and as shown in FIGS. 2-5, a front side 98 of the fuel pump unit 10 is provide by the pump cover 16. With this orientation, the pump unit 10 has a top side 99, a bottom side 100, a right side 101, and a left side 102. The main fuel inlet port 28 is provide along the right side 101 of the pump 10 in the pump cover 16, and is in a conventional position to connect to existing tank intake lines (e.g., such as intake line 13 as shown) without additional plumbing. Likewise, the main fuel outlet port 41 is on the left side of the pump unit 10 in the pump body 14, and is in a conventional position to connect to existing outlet passage conduits (e.g., tubing 38) without additional plumbing. The inlet side port 88 formed in the bottom side 100 (adjacent a return port 89 that provides an option of connecting to the tank 12) receives the electronic inlet side pressure gauge 84. Because the solenoid valve 58 occupies the top side of the pump body 14, the other pressure gauge 86 is mounted into the front side 98 of the pump unit 10 through the outlet side port 92 formed into the front side of the pump cover 16. To accommodate the outlet side port 92 and communicating pressure passage 94, the pump cover 16 may include a raised boss or projection 105 to ensure sufficient material is provided to form the port 92 and passage 94.

Illustrated in FIG. 7 is another embodiment of a fuel oil pump unit 200 for supplying fuel to a combustion chamber of a furnace or boiler. The configuration of the fuel oil pump unit 200 within the fuel system of a furnace or boiler is substantially similar to the configuration of fuel pump 10 and related components as illustrated in FIG. 1.

Referring to FIG. 8, the fuel oil pump unit 200 includes a pump body 210 and a pump cover 212 that can be bolted together by a plurality of bolts 214. To pump the fuel, a rotating gear pump 220 is incorporated with pump body 210 as described above. For mounting the gear pump 220 and pump cover 212, the pump body 210 includes a generally planer mounting face 216. The fuel pump may also include a regulating valve assembly operated by a solenoid valve 222 for controlling the fuel flow to an outlet port 224 formed in the pump body 210 that communicates with the burner.

The pump 220 communicates with and intakes fuel from a local fuel oil reservoir 228 that receives fuel oil from a main fuel oil supply. The local reservoir 228 corresponds to a volume formed between the pump body 210 and the pump cover 212 when they are bolted together. To form the volume, the pump cover 212 includes a front side 230 and a rearward extending peripheral wall 232 that offsets the front side from the pump body 210. A plurality of bolt slots 215 are provided within the pump cover 212 and disposed through the peripheral wall 232 for accommodating the bolts 214. The front side 230 and peripheral wall 232 thereby enclose the local reservoir 228. To transfer fuel from the main fuel oil supply to the local reservoir 228, the pump cover 212 includes an intake port 234 to which an intake line can be connected. For filtering fuel, a strainer 236 can be provided within the local reservoir separating the intake port 234 from the pump 220.

To prevent fuel from leaking from the local reservoir 228, the fuel pump 200 includes a gasket 240 located between the pump body 210 and pump cover 212 for forming a seal when the two are bolted together. As illustrated in FIG. 9, the gasket 240 can be formed as a generally planer gasket sheet 242 having an outer periphery 244 and an inner periphery 246. The gasket sheet 242 can be made from any suitable material such as a foam material or fiberboard.

The outer periphery 244 corresponds generally to the shape and dimensions of the pump cover 212 and is thereby compressed between the peripheral wall 232 and mounting face 216 when the fuel pump 200 is assembled. In the illustrated embodiment, the outer periphery and the pump cover are both generally rectangular in shape. To accommodate the pump 220 and strainer 236 that protrude from the mounting face 216, the inner periphery 246 forms an opening that may fit around the strainer. In the illustrated embodiment, the shape of the inner periphery 246 and the strainer 236 are circular.

To accommodate the bolts 214 used to hold the pump cover 212 and the pump body 210 together, the gasket sheet 242 can include a plurality of bolt holes 250. In the embodiment illustrated in FIG. 9, wherein the pump cover 212 and outer periphery 244 are rectangular in shape, the location of the bolt holes 250 corresponds to the four corners of the gasket sheet 242 and are spaced radially outward from the inner periphery 246. The pattern of bolt holes 250 thereby aligns with a plurality of threaded holes 218 disposed into the mounting face 216 as illustrated in FIG. 8.

Referring to FIG. 8, to accommodate the inlet side and outlet side electronic pressure gages 280, 282 for providing feed back from the fuel oil pump unit 200, as described above, the fuel oil pump unit includes a second inlet side port 284 and a second outlet side port 286. The second inlet side port 284 is disposed through the bottom side of the pump body 210 and is in constant fluid communication with the local reservoir 228 upstream of the pump 220. The second outlet side port 286 is disposed through the front side 230 of the pump cover 212 and communicates with the first outlet port 224 in the pump body 210 by way of a passageway 290 through the pump cover and pump body. The second outlet side port 286 is therefore upstream of the pump 220 in constant communication with the pressure generated by the pump when the solenoid valve 222 is open.

To allow fluid communication across the passageway 290, as illustrated in FIGS. 8 and 9, the gasket includes an aperture 252 that corresponds to the location of the passageway. The aperture 252 is disposed through the gasket sheet 242 partway between the outer periphery 244 and the inner periphery 246. Surrounding the aperture 252 is a sealing ring 254 of gasket material that functions to seal the passageway 290. As illustrated in FIG. 9, with the circular inner periphery 246, the aperture 252 and sealing ring 254 are located radially outward from the inner periphery generally toward the bolt hole 250 in the corner.

Referring to FIG. 8, as will be appreciated by those of skill in the art, because the passageway 290 is in fluid communication with the downstream side of the pump 220, the passageway will typically experience a higher pressure than the upstream local reservoir 228. In fact, the passageway 290 may experience a higher pressure than the environment surrounding the fuel oil pump unit 200. The high pressure of the fuel in the passageway will tend to force fuel from the passageway into the sealing ring of gasket material at the location of the aperture and toward the inner and outer peripheries. Fuel forced to the inner periphery will be safely received in the low pressure local reservoir. However, fuel forced to the outer periphery may leak or spray from the fuel oil pump unit to the environment. In addition to creating a messy fuel spill, the leaking fuel presents a dangerous fire hazard especially around a burner or furnace.

Therefore, to prevent fuel from leaking to the outer periphery, the gasket 240 includes a leakage collection channel 256 proximate to the aperture 252 for returning fuel to the local reservoir. In the embodiment illustrated in FIG. 9, the collection channel 256 is located between the aperture 252 and the outer periphery 244 includes a first leg 258 and a second leg 259 interconnected by an intermediate portion 260. Each leg is substantially straight and arranged so as to surround the aperture. Accordingly, the collection channel is generally U-shaped with each leg and the intermediate section forming a corner where they intersect. The sealing ring 254 is formed by the gasket material remaining between the collection channel 256 and the aperture 252.

Because of the straight shape of the legs and intermediate portion, the sealing ring has a generally square outline that effectively adds more gasket material between the aperture and the collection channel, especially around the corners. The additional material and square corners of the sealing ring also provides the thin gasket sheet with added strength at a critical location that may be subject to high fluid pressure and pressure fluctuations. Referring to FIG. 8, it will also be appreciated that the increased strength of the sealing ring 254 is advantageous when the passageway 290 is disposed at a non-perpendicular angle to the mounting face 216 or when the portion of the passageway in the pump cover must be axially offset from the portion of the passageway in the pump housing. Such alignments may be necessitated by the arrangement of the other components of the fuel pump unit.

As illustrated, the intermediate portion 260 is located between the aperture 252 and the outer periphery 244 with the first and second legs 258, 259 extending towards the inner periphery 246. The first and second legs 258, 259 may be parallel to each other or, as illustrated in FIG. 9, may diverge from each other as they extend from the intermediate portion 260. Accordingly, the corners formed by the intersection of the intermediate portion and the legs may appear as right angles or obtuse angles. The collection channel 256 may be disposed partially or completely through the gasket sheet 242. As will be appreciated from FIG. 8, when the fuel oil pump unit 200 is assembled the ends of the first and second legs 258, 259 will be in communication with the local reservoir 228. Accordingly, any fuel leaking from the passageway 290 toward the outer periphery 244 will encounter the collection channel 256 and be returned via the first and second legs to the local reservoir. Depending upon the precise dimensions of the cover plate 212 and the local reservoir 228, the first leg 258 may be longer than the second leg 259.

Referring to FIG. 8, as described above, to accommodate the solenoid valve 222 the first outlet side passage 286 is disposed through the pump cover 212 near the top of the pump cover. Accordingly, the passageway 290 is disposed through the pump body 210 near the top of the pump body. To correctly position the aperture 252 and collecting channel 256, in the embodiment illustrated in FIG. 9, the gasket 240 can be configured into an upper portion and a lower portion as well as a first side portion and a second side portion. The rectangular gasket is thereby arranged into an upper first quarter 262, an upper second quarter 264, a lower first quarter 266, and a lower second quarter 268. The aperture 252 and collecting channel 256 are positioned in the upper first quarter 262.

To simplify assembly of the fuel oil pump unit, the gasket 240 can include a second redundant aperture 270 and a second redundant collecting channel 274 positioned in the upper second quarter 264 and arranged to mirror the first aperture 252 and collecting channel 264. Accordingly, the second redundant collecting channel includes a first leg 276 and a second leg 277 that are interconnected by an intermediate portion 278, each of which is substantially straight. The second redundant aperture 270 and second redundant collecting channel 274 can be spaced apart by a second sealing ring 272 of gasket material. The gasket 240 is therefore symmetrical enabling assembly of the fuel pump without having to orient the first and second side portions of the gasket with the pump body and pump cover.

In an embodiment, to ensure that the collecting channel communicates with the local reservoir, grooves can be machined or otherwise formed into the pump cover. Specifically, referring to FIG. 10, the pump cover 212 includes a backside 292 offset from the front side 230 and corresponding to the peripheral wall 232. As illustrated, the bolt slots 215 are disposed through the backside 292. Formed into the backside 292 and offset to one side of the passageway is a groove 294. The groove 294 is formed so as to access the volume that defines the local reservoir. Referring to FIG. 8, as will be appreciated, when the fuel pump is assembled, the groove aligns with the shorter second leg 259 to complete fluid communication between the collecting channel 256 and the local reservoir 228.

All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirely herein.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. A fuel pump unit for pumping fuel from a fuel tank to a combustion chamber, the fuel pump unit comprising:

a gear pump adapted to pump fuel;

a pump body housing the gear pump, the pump body including an outlet port downstream of the gear pump for outputting pumped fuel;

a pump cover mounted to the pump body;

a local reservoir defined between the pump body and the pump cover, the local reservoir being upstream of the gear pump;

a pressure gauge port in the pump cover connected by a passageway extending through the pump cover and the pump body to communicate with the outlet port; and

a gasket between the pump body and the pump cover to seal the local reservoir, the gasket including an aperture corresponding to the passageway to allow communication therethrough, the gasket including a leakage collection channel partially surrounding the aperture, the leakage collection channel having a first straight leg, a second straight leg, and a straight intermediate portion interconnecting the first and second straight legs, the leakage collection channel adapted to communicate and return leaked fuel from the passageway to the local reservoir to prevent external fuel leakage.

2. The fuel pump unit of claim 1, wherein the leakage collection channel is located partially between aperture and an outer periphery of the gasket.

3. The fuel pump unit of claim 2, wherein the gasket includes a sealing ring of gasket material surrounding the aperture, the sealing ring separating the aperture and the leakage collection channel and adapted to prevent leakage of fuel from the passageway between the pump cover and the pump body, and in the event of leakage past the sealing ring leaked fluid is adapted to be collected in the collection channel and returned to local reservoir.

4. The leakage channel of claim 3, wherein at least one leg is in fluid communication with the local reservoir.

5. The fuel pump unit of claim 4, wherein the intermediate portion is arranged between the aperture and the external environment, the first and second straight legs projecting inward from the intermediate portion toward the reservoir.

6. The fuel pump unit of claim 1, wherein the gasket comprises a generally planar sheet, the collection channel extending completely through the generally planar sheet.

7. The fuel pump unit of claim 1, wherein the gasket includes a second redundant aperture and a second redundant leakage collection channel proximate the second redundant aperture symmetric to the first aperture and first leakage connection channel, the redundant aperture and the redundant leakage collection channel being non-functional when mounted between the pump cover and the pump body.

8. A pump gasket for sealing a low pressure local reservoir defined between a pump body having a downstream high pressure outlet port and a pump cover having a passage, the gasket comprising:

a generally planer gasket sheet having an outer periphery and an inner periphery defining an opening;

an aperture disposed through the gasket sheet, the aperture corresponding to the passage and the outlet port; and

a leakage collection channel in the gasket sheet, the leakage collection channel including a first straight leg, a second straight leg, and a straight intermediate portion interconnecting the first and second straight legs, the leakage collection channel partially surrounding the aperture and adapted to communicate with the low pressure local reservoir when the pump gasket is mounted between the pump body and the pump cover.

9. The pump gasket of claim 8, wherein the first and second legs are located on opposing sides of the aperture.

10. The pump gasket of claim 9, wherein the leakage collection channel is disposed through the gasket sheet.

11. The pump gasket of claim 8, wherein the outer periphery is generally rectangular and the inner periphery is generally circular.

12. The pump gasket of claim 11, further comprising a plurality of bolt holes, each bolt hole corresponding a corner of the rectangular outer periphery.

13. The pump gasket of claim 8, wherein the gasket sheet is distinguished into an upper first quarter, an upper second quarter, a lower first quarter, and a lower second quarter, and wherein the aperture and the leakage collection channel are located in the upper first quarter.

14. The pump gasket of claim 8, wherein the first straight leg and the second straight leg intersect the straight intermediate portion at defined corners.

15. The pump gasket of claim 13, further comprising a second redundant aperture and a second redundant leakage collection channel, the second aperture and second leakage collection channel located through the upper second quarter.

16. The pump gasket of claim 15, wherein the second redundant leakage collection channel includes a first straight leg, a second straight leg, and an straight intermediate portion interconnecting the first and second legs.

17. The pump gasket of claim 16, wherein the gasket sheet is symmetrical between the upper and lower first quarters and the upper and lower second quarters.

18. A pump gasket for sealing a low pressure local reservoir defined between a pump body having a downstream high pressure port and a pump cover having a slanted passage oriented at a non-perpendicular angle to the mating surfaces of the pump body and pump cover, the gasket comprising:

a generally planer gasket sheet having an outer periphery and an inner periphery defining an opening;

an aperture disposed through the gasket sheet, the aperture corresponding to the passage and the outlet port;

a leakage collection channel in the gasket sheet, partially surrounding the aperture and in fluid communication with low pressure reservoir; and

means in the planar gasket sheet between the channel and the aperture for providing sufficient strength planar gasket sheet to prevent leakage along the slanted passage to the channel when mounted between the pump body and pump cover and when the slanted passage is subjected to high fuel pressure.

19. The pump gasket of claim 18, further comprising a plurality of bolt holes disposed through the gasket sheet material.

20. The pump gasket of claim 19, wherein the gasket sheet has a rectangular outer periphery and a circular inner periphery.

21. The pump gasket of claim 19, wherein the means includes a plurality of legs, each adjacent set of said legs intersecting at a defined corner.